Adjustable rotary operative fastener stud



June 19, 1945. F. x: JOHNSON ADJUSTABLE ROTARY OPERATIVE FASTENER STUDFiled Aug. 24, 1943 A Ii.

Patented Jene 19, i945 anmsranm'noranrforaaama ras'rENaa STUD Frank E.Johnson, Malden, Mass., asslgnor to United-,Carr Fastener Corporation,Cambridge, Mass., a corporation oi' Massachusetts Application August 24,1943, Serial No. 499,859

4 Claims. (OI. v2422l) The present invention relates to rotaryvoperative fastener studs of the type employed in rotary operative typefasteners, such as are used for` securing together aircraft cowlingsheets, and the invention aims generally to improve existing studs.

Rotary operative fasteners as used for aircraft cowling usually comprisea rotary, stud member mounted in one of the cowling sheets and adaptedto be. passed through an aperture in the other sheet and interlockinglyengage a cooperative fastener member attached thereto as the result of apartial rotation of the stud. s

l One type of fastener for such purpose comprises a studhaving a headand shank, the latter being provided with radial arms or extensions forengagement with a locking surface of a female or socketfastener member.Such female or socket fastener member. may be of any approved form, forexample as shown in my Patent No. 2,309,731, dated February 2, 1943, orthe patent of William it Bedford, Jr., No. 2,306,928, dated December`29, 1 42.

Rotary operative type fasteners for aircraft cowling must be operativeto secure the cowling sheets together under strong clampingr pressure.In modern high speed aircraft there is considerable air pressure exertedbetween the cowling sheets tending to separate them and in order toobtain maximum results the proper length of stud must be carefullyselected for each given installation. Furthermore, the cowling sheets ofvarious types of aircraft varies in thickness and to insureproperclamping pressure it has been found necessary forsmanufacturers toprovide an assortment of sizes or lengths of stud, there beingapproximately nine different lengths provided to acconlimodate studlengths from .040 inch to .25D inc The present invention aims to improverotary operative fasteners of the above described type by the provisionof an improved stud that may be quickly and simply adjusted to vary theoperating stud length or distance between the head and radial armsthereof.

Illustrative of the invention reference is made to the accompanyingdrawing and annexed description illustrating and describing twopreferred embodiments of the invention.

In the drawing:

Fig. 1 is a longitudinal central sectional view through one type ofrotary operative fastener installation as employed for aircraft cowlingemployingmy improved stud;

Fig. 2 is a side elevation of one embodiment of my improved stud;

.FIg.,.3 is a Fig. 2; K Pig. 4 is a central vertice..` sectional viewthereof Fig. 5 is a horizontal sectional viewasftakemon Y. f

the line 5--5 of Fig. 4;

Fig. 6 is a view similarto Fig. 4 illustrating an alternativeconstruction;

Fig. 'lis a view similar'to Fig. 2 of the form of stud illustrated inFig. 6; and

Fig. -8 is a view similar to Fig. 3 of the form of l stud illustrated inFig. s.

Referring -to the drawing, the spring or socket member for my rotarystud member may be of the type commonly employed in aircraft cowlingfasteners, for example, of the type shown in my Patent No. 2,309,731,dated February 2, 1943, wherein a female or socket fastener member I issuitably attached t`o one face of an apertured support 2 and is providedwith an outwardly dished stud-receiving seat 3 apertured as at 4 toreceive a cooperating rotary stud member 5 rotatably mounted in a part 6to be attached to the support 2. .The stud is preferably of the typehaving radial arms I1, which 'advantageously may be formed by means of acrosspln mounted in the stud, which arms engage the stud-receiving seat3 upon partial rotation of the former and serve to hold the parts 2 and6 in secure fastened relationship.

In order to maintain the parts 2 and i securely in fastened relationshipagainst forces tending to separate them, it is important that the studlength, as determined by the distance between the head of the stud andradial arms, be accurately proportioned according to the distancebetween the outer face of the part 6 engaging the stud head and thestud-receiving seat.

'I'he present invention provides an improved rotary stud member having ashank and head and radial arms adjustable longitudinally of the studshank so that the effective stud length, i. e., the distance between thehead and arms, may be varied readily to accommodate installations ofvarious sizes and thicknesses.

According to the form of invention illustrated in Figs. 2 to 5, theimproved stud member B comprises a shank portion I9 having a head I I atone end thereof, which head may be tapered as shown to seat in a conicaldepression 1 in the part i surrounding the aperture 8 therein, and thusprovide a fastening in which the head is substantially ilush with theouter-face of the part l. The stud may be rotatably retained in theaperture I by view of the stud at right angles tol inserting the springsuitablemeans, as for example a spring locking ring I seated in'anannular groove 9* as is customary in the art.

The shank Il is provided with an axial bore I2, preferably throughoutthe length thereof, which bore opens through the nose end Il of theshank' and which is threaded or tapped as at Il throughout a portion ofthe outer end thereof to receive a threaded plug or screw member Iltherein. I'he side walls oi' the bored shank It are provided withopposed elongated slots II intermediate the head and end of the shank tadiustablyreceive the radial arms I1 carried by an insert il slidablymounted in the bore. The insert advantageously may be in the form of acylindrical plug loosely fitted in the bore and formed with a transversepress-ntted a pin so as to provide the radial arms I1 extending throughand beyond the slots Il. A spring member It is preferably positioned inthe bore between the inner end thereof and the insert to maintain theinsert in tensioned engagement with the screw I5.

The stud may be readily assembled by rst Il in the bore, litting theinsert I8 in the bore above it and securing the insert in the bore bypress-fitting the crosspin in the insert with its arms I1 extendingthrough the slots it. The spring I! obviously acts on the insert tomaintain the arms I1 in the outer ends of the slots It. Adjustment ofthe insert I8 and radial arms I1 toward the headmay be effected bysimply rotating the screw Il in the threaded bore Il in the nose end ofthe stud.

The form of adjustable stud shown in Figs. 6, 7 and 8 is similar to theform above described except that the insert It* and screw I* may bepermanently connected and the necessity for the spring I! eliminated.

According to this form It* is formed with of invention the insert arivet Il which extends and is upset over the marginal edge of thecounterbore. The insert It* is thus swivelly connected to the screw II*so that rotation of the screw in the threaded bore Il effects adjustmentof the insert and arms I1 longitudinally of the stud shank. m

According to the invention the screw Il or Ill may be sulliciently longto extend beyond the nose I3 or the stud and be fitted with a lockingnut 2! threaded thereon to lock the screw in its adiusted position inthe bore Il.

Although I have illustrated and described preferred forms of myinvention, I do not wish to be limited thereby because the scope of myinvention is best defined by the following claims.

aperture in which is through a counterbore 2l of a hollow screw It* Iclaim:

l. A rotary stud member for separable rotary operative fastenerscomprising a shank formed with a head at one end thereof, said shank`having an axial bore opening through an end .thereof and elongated slotsin the sides thereof, an insert mounted in said shank bore and havingradial extensions extending through and beyond said slots. spring meansin saidvbore normally urging said insert and extensions away from said-shank head, and a member adjustably mounted in the open end of saidbore fory limiting movement of said insert. A 2. A rotary stud memberfor separable rotary operative fasteners comprising a shank formed withahead at one end thereof, said shank having an axial bore openingthrough an end thereof and elongated slots in the sides thereof. aninsert mounted in said shank bore and having radial extensions extendingthrough and beyond said slots, spring means in said bore normally urgingsaid insert and extensions away from said shank head, and means havingadjustable screw threaded engagement with the walls ofthe shank bore foradjusting the position of the extensions in said slots, said last namedmeans providing a rigid abutm ent for limiting movement of saidextensions in said slots in a direction away from said head.

3. A stud member for separable rotary operative fasteners comprising ashank formed with a head at one end, said shank having an axial borethroughout substantially the length thereof and opposed elongated slotsin the sides thereof, an insert mounted in said bore, a pin iitted insaid insert and extending through and beyond said slots, and a screwthreaded in the outer end of said bore for engaging said pin andadjusting said pin in said slots, and spring means for maintaining saidinsert in engagement with said screw. v

4. A stud member for separable rotary operative fasteners comprising ashank formed with a head at one end, said shank having an axial yborethroughout substantially the length thereof and opposed elongated slotsin the sides thereof, an insert mounted in said bore, a pin i'itted insaid insert and extending through and beyond said slots. le. screwthreaded in the outer end of said bore for engaging said pin andadjusting said pin in said slots and a spring positioned in said borevfor maintaining said insert in engagementwith said screw.

